工作站與量測機台間自動化回饋與控制系統之構建

Abstract

良好的製程流程控制（process plow control）是每個製造工廠努力的目標。產品在製造過程中存在多種變異的因素。因此工廠需要一個可以改善製程變異的品質監控系統。在製造流程中有許多的工作站，半成品在工作站加工所需的製程後，該半成品便會經由輸送系統傳送到下一個工作站進行量測，監視是否產生變異，如果量測值合乎規格則繼續將半成品往下一工作站傳送。如果量測值不合規格，則由工程師進入工作現場對工作站的生產機台進行參數的微調，使下一批半成品再經過這個工作站時，所進行的加工流程可以符合品管部門的要求。這個從生產、量測、發現異常、處理機台直到恢復生產的過程需要花費相當長的工作流程。因此，本研究的主要目的是在工作站和量測機台間建立一個自動化的控制與回饋系統，以節省製程流程控制之人力和時間。 本研究首先利用實驗設計法(experiment of design; DOE)找到影響的顯著因子，再利用迴歸分析建構量測值和製程參數的數學方程式並且將此數學方程式用於建立製程自動化回饋系統。此系統可以在產品的生產過程中持續收集產品的製程參數值和量測值，再計算出新的製程參數期望值並且輸入到機台內，使下一批半成品在製造時可以獲得品質管制的目標值，減少製程上的變異。本研究最後由一個實際8吋晶圓廠之案例來說明所提出之自動回饋系統確實有效可行。 [關鍵字] 實驗設計、回饋控制、品質監控

Building a system to effectivelyl maintain the quality in the process flow is the main purpose a manufacturing factory. When a product was produced as planned by the manufacturing flow, insert some measurement stations in the manufacturing flow to make sure the quality of the product will be kept in the good level and well controlled. Products usually contain many engineering variations in the process flow. Mostly of the variations came from the production equipments in the work station, e.g., the shift or offset of the controllers for gas flow, pressure, temperature, etc. The quality system needs to pay more cost of manpower to correct the shift or variation of the equipment. Thus, the purpose of this study is tried to design a quality control system in automation manufacturing. This system collect the response (measurements) and parameters setting valves in the equipment. The expected setting value in the equipment could be found in this system and replace the previous setting value in the equipment. This feedback system was implemented in a 8” wafer fabrication plant in Hsinchu Taiwan and is verified to be effective. Key words: DOE, feedback control, quality monitor and control